Disinfection of instruments

ABSTRACT

The invention relates to a powdered disinfectant containing a peroxide, an acylating agent and nonionic surfactants and to the use of this disinfectant for disinfecting surfaces and instruments, particularly in the medical field.

The present invention relates to a powdered disinfectant containing aperoxide, an acylating agent and nonionic surfactants and to the use ofthese disinfectants for disinfecting surfaces and instruments, moreparticularly in the medical field.

Numerous aqueous preparations containing a wide variety of antimicrobialdisinfecting ingredients have been proposed over the course of time forthe chemical disinfection of instruments. Preparations based onaldehydes have been most widely used in practice, although preparationscontaining quaternary ammonium compounds, phenols, alcohols and otheractive disinfecting ingredients are also used. Preparations based onperoxidic active ingredients, more particularly peracetic acid, on theother hand, have rarely been used for this application. This is largelydue to the poor stability in storage of these aqueous preparations.Owing to the broad antimicrobial activity of peroxides, attempts havebeen made to overcome the drawback of poor stability in storage. Thus,it has been proposed, for example in DE-A-26 55 599 and 28 15 400, toprepare the aqueous preparations required for disinfection from morestable precursors, more particularly from sodium perborate and acidanhydrides, just prior to use. According to DE-A-27 01 133, the aqueouspreparations are obtained from hydrogen-peroxide-yielding compounds andaromatic acyloxycarboxylic acids. However, only a few of these compoundslead to disinfecting solutions with sufficiently broad activity andthese acylating agents mixed with the necessary inorganic peroxides canonly be stored for a limited time owing to decomposition reactions.Sekusept powder is the name given to a commercially available productwhich forms a disinfectant preparation when dissolved in water throughthe reaction of sodium perborate with tetraacetylethylenediamine (TAED).This product, which is based on an N-acyl compound, has a broad activityspectrum and is stable in storage. Although a high standard ofdisinfection of medical instruments has been achieved in this way, animprovement in peroxide systems is still being sought to eliminate theremaining gaps in activity and drawbacks in service. A particulardrawback of these powdered systems is that they dissolve only veryslowly in water. This leads to the disadvantage, on the one hand, thatthe desired disinfectant concentration is not fully available until avery late stage. On the other hand, there is the additional risk thatundissolved constituents will remain in the system to be disinfected oron the surface to be disinfected and will not be rinsed away.

It was accordingly an object of the present invention to provide anadequate disinfectant concentration within a short time and thus tominimise the risk of residues in the system and on surfaces.

A further object was to destroy microorganisms, including mycobacteria,in a shorter time.

This object has been achieved by the preparations according to theinvention.

Accordingly, the present invention relates to a powdered disinfectantbased on active oxygen containing a peracetic acid-generating systemconsisting of a peroxide and an acylating agent together with nonionicsurfactants.

Preferably, the above-mentioned nonionic surfactants are free fromalkoxylated alkyl phenols and comprise ether alcohols which arestraight-chained or methyl-branched in the 2-position and correspond tothe formula:R—O—(PO)₁₋₂-(EO)₆₋₈—H  (I)where the alkyl and alkenyl radicals R are made up as follows:

-   -   C₈=0 to 5% by weight;    -   C₉₋₁₀=75 to 90% by weight;    -   C₁₁₋₁₂=5 to 15% by weight;    -   C₁₃₋₁₄=4 to 10% by weight;    -   C₁₅₋₁₆=0 to 3% by weight.

The above-mentioned peroxide is preferably selected from the groupconsisting of sodium perborate monohydrate, sodium perboratetetrahydrate, sodium percarbonate and mixtures thereof.

The above-mentioned acylating agent is preferably selected from thegroup consisting of tetraacetylglycoluril, tetraacetylethylenediamine,diacetylhexahydrotriazinedione and mixtures thereof.

Other N-acyl compounds which have also been described in detergentchemistry as bleach activators for reactions with hydrogen peroxide inalkaline washing liquors may obviously also be used. Suitable N-acylcompounds are those, in particular, which comprise a further keto groupon the acyl group-carrying nitrogen and/or in which the nitrogen is partof a heterocyclic ring system. Examples of suitable N-acyl compoundsinclude the multiply acylated alkylenediamines such astetraacetylethylenediamine, acylated glycolurils, predominantlytetraacetylglycoluril, N-acylated hydantoins, hydrazides, triazoles,triazines, urazoles, diketopiperazines, sulfurylamides, lactams andcyanurates.

The disinfectant according to the invention preferably contains

-   -   10 to 70% by weight, preferably 15 to 60% by weight of the        above-mentioned peroxide,    -   10 to 40% by weight, preferably 15 to 30% by weight of the        above-mentioned acylating agent,    -   0.1 to 10% by weight, preferably 0.5 to 5% by weight, of the        above-mentioned nonionic surfactant and    -   to 100% by weight of soluble inorganic salt and optionally        further auxiliaries as remainder.

Further auxiliaries include alkalising agents, complexing agents forwater hardness, complexing agents for heavy metal ions and water-solubleinorganic salts, corrosion inhibitors and other surfactants. The amountsof these auxiliaries in the preparations may vary widely, depending onthe intended activity. It does not usually exceed about 3% by weight andis preferably between about 0.001 and about 1% by weight, based on thetotal preparation.

Sodium triphosphate is mentioned primarily as a complexing agent for thewater hardness, though other polyphosphates, salts of nitrilotriaceticacid and salts of organic polycarboxylic acids, for example citric acid,or of polymeric polycarboxylic acids, for example acrylic acid maleicacid copolymers, may also be used for this purpose. Sodium triphosphate,which simultaneously acts as an alkalising agent, is particularlypreferred.

Suitable complexing agents for heavy metal ions which have a decomposingaction on peroxide compounds predominantly include aminopolycarboxylicacids and salts thereof, for example ethylenediaminetetraacetic acid,but more particularly aminopolyphosphonic acids such asethylenediaminetetramethylene phosphonic acid or also hydroxyethanediphosphonic acid and the salts thereof.

Water-soluble salts can act as fillers or builders, such as sodiumsulphate, if they do not simultaneously have an alkalising activity,such as sodium carbonate and sodium silicate. Suitable corrosioninhibitors include, more particularly, alkylphosphonic acids, of whichoctane phosphonic acid is particularly preferred. Further possibleauxiliaries include dyes, perfume and solubilising additives.

In use, the disinfectant is normally diluted with water.

It is preferably dissolved in water in a quantity of 1 to 10% by weight.

In a preferred embodiment, the disinfectant according to the inventionis used for disinfecting surfaces and/or instruments.

It is also preferable to use the disinfectant according to the inventionto destroy gram-positive bacteria and/or to destroy mycobacteria and/orto destroy viruses.

EXAMPLES

1. Production of the Active Ingredient Solution

Three different powdered mixtures each consisting of

-   -   50% by weight sodium perborate monohydrate and 25% by weight    -   TAED powder and    -   a) no surfactant    -   b) 2% by weight ABS (alkylbenzenesulfonate) and    -   c) 2% by weight Dehydol 980        were used as starting materials.

Corrosion inhibitors, complexing agents and further inorganic salts wereused to make up 100% by weight.

The capacity of these different powder formulations 1a) to 1c) todissolve in water was investigated without stirring or other movement ina first experiment.

For this purpose, 8 g of each of the powder formulations 1a) to 1c) wereintroduced into 100 ml of tap water respectively at room temperature.

It was found that formulations 1a) and 1b) required more than 1 hour todissolve. In addition, a sediment also formed in the case of powderformulation 1b).

In the case of powder formulation 1c), on the other hand, the powder haddissolved within 1 hour. No sediment had formed either.

Explanation:

Dehydol 980 is an ether alcohol which is methyl-branched in the2-position, of formulaR—O—(PO)₁₋₂-(EO)₆₋₈—H  (I)wherein the alkyl and alkenyl radicals R are made up as follows:

-   -   C₈=0 to 5% by weight;    -   C₉₋₁₀=75 to 90% by weight;    -   C₁₁₋₁₂=5 to 15% by weight;    -   C₁₃₋₁₄=4 to 10% by weight;    -   C₁₅₋₁₆=0 to 3% by weight.        2. Test for Effectiveness Against the Gram-Positive Bacterium        Enterococcus hirae

Application solutions for microbiological investigations were preparedusing powder formulations 1a) and 1c) by dissolving 12.5 g of each in100 ml of tap water respectively.

These solutions were tested for the gram-positive bacterium Enterococcushirae by the quantitative germ carrier test under dirty conditions inaccordance with the new DGHM guideline (Status 1.3.2001). The followinglog reduction factors (triple determination in each case) were thusestablished: Contact time 1c) 1a) 1 min 3.06/2.23/3.1 0.53/0.61/0.48 5min 3.22/3.81/2.98 1.74/1.41/1.33 10 min  6.8/6.8/6.8 3.72/3.46/3.8

The antimicrobial activity was a further advantage detected in theformulations according to the invention.

3. Test for Activity Against the Poliovirus

Application solutions for microbiological investigations were preparedusing powder formulations 1a) and 1c) by dissolving 12.5 g of each in100 ml of tap water respectively.

These solutions were tested against the poliovirus in the quantitativesuspension test in accordance with the DVV guideline. The followingaverage log reduction factors (triple determination in each case) werethus established: Contact time 1c) 1a) 5 min 1.5 1.5 10 min  3.3 2.6

The virological test results thus reveal a further advantage.

1-9. (canceled)
 10. A powdered peracetic acid disinfectant compositioncomprising: (a) a peroxide; (b) an acylating agent; and (c) a nonionicsurfactant selected from the group consisting of linear or2-methyl-branched ether alcohols having the formulaR—O—(PO)₁₋₂-(EO)₆₋₈—H wherein R is C₈=0 to 5% by weight of the nonionicsurfactant in the composition; C₉₋₁₀=75 to 90% by weight of the nonionicsurfactant in the composition; C₁₋₁₂=5 to 15% by weight of the nonionicsurfactant in the composition; C₁₃₋₁₄=4 to 10% by weight of the nonionicsurfactant in the composition; and C₁₅₋₁₆=0 to 3% by weight of thenonionic surfactant in the composition and the nonionic surfactant isfree of alkoxylated alkyl phenol.
 11. The composition of claim 10,wherein the peroxide is selected from the group consisting of sodiumperborate monohydrate, sodium perborate tetrahydrate, sodiumpercarbonate, and mixtures thereof.
 12. The composition of claim 10,wherein the acylating agent is selected from the group consisting oftetraacetyl glycoluril, tetraacetyl ethylenediamine, diacetylhexahydrotriaone dione, and mixtures thereof.
 13. The composition ofclaim 10, further comprising from about 10 to about 70 wt. % peroxide;from about 10 to about 40 wt. % acylating agent; and from about 0.1 toabout 10 wt. % nonionic surfactant.
 14. The composition of claim 10,further comprising: from about 15 to about 60 wt. % peroxide; from about15 to about 30 wt. % acylating agent; and from about 0.5 to about 5 wt.% nonionic surfactant.
 15. The composition of claim 10, furthercomprising a soluble inorganic salt.
 16. The composition of claim 10,further comprising additional auxiliary ingredients.
 17. A method ofdisinfecting a surface comprising: (a) providing a peracetic acid usecomposition in an amount effective to kill an organism selected from thegroup consisting of gram-positive bacteria, mycobacteria, viruses, andmixtures thereof, said use composition comprising from about 1 to about10 wt. % of a powder diluted in water, said powder comprising: (i) aperoxide; (ii) an acylating agent; and (iii) a nonionic surfactantselected from the group consisting of linear or 2-methyl-branched etheralcohols having the formulaR—O—(PO)₁₋₂-(EO)₆₋₈—H wherein R is C₈=0 to 5% by weight of the nonionicsurfactant in the composition; C₉₋₁₀=75 to 90% by weight of the nonionicsurfactant in the composition; C₁₁₋₁₂=5 to 15% by weight of the nonionicsurfactant in the composition; C₁₃₋₁₄=4 to 10% by weight of the nonionicsurfactant in the composition; and C₁₅₋₁₆=0 to 3% by weight of thenonionic surfactant in the composition and the nonionic surfactant isfree of alkoxylated alkyl phenol; and (b) applying said use compositionto a surface.
 18. The method of claim 17, wherein the surface is amedical instrument.
 19. The method of claim 17, wherein the peroxide isselected from the group consisting of sodium perborate monohydrate,sodium perborate tetrahydrate, sodium percarbonate, and mixturesthereof.
 20. The method of claim 17, wherein the acylating agent isselected from the group consisting of tetraacetyl glycoluril,tetraacetyl ethylenediamine, diacetyl hexahydrotriaone dione, andmixtures thereof.
 21. The method of claim 17, the powder furthercomprising from about 10 to about 70 wt. % peroxide; from about 10 toabout 40 wt. % acylating agent; and from about 0.1 to about 10 wt. %nonionic surfactant.
 22. The method of claim 17, the powder furthercomprising: from about 15 to about 60 wt. % peroxide; from about 15 toabout 30 wt. % acylating agent; and from about 0.5 to about 5 wt. %nonionic surfactant.
 23. The method of claim 17, the powder furthercomprising a soluble inorganic salt.
 24. The method of claim 17, thepowder further comprising additional auxiliary ingredients.
 25. Apowdered peracetic acid disinfectant composition comprising: (a) aperoxide; (b) an acylating agent; and (c) a nonionic surfactant selectedfrom the group consisting of linear or 2-methyl-branched ether alcoholshaving the formulaR—O—(PO)₁₋₂-(EO)₆₋₈—H wherein R is at least about 75% by weight C₁₀ ofthe nonionic surfactant in the composition; and the nonionic surfactantis free of alkoxylated alkyl phenol.